Patterns in Testing Concurrent Programs with Non-deterministic Behaviors

Concurrent programs are hard to test because of the nondeterminism inherit in them. Since non-determinism is one of the major sources of bugs, it is important to to be tested. We studied the test suites of four open source concurrent libraries and discovered that the tests fall into three different patterns. One of the patterns avoids testing nondeterminism while the other two control the schedule of the program execution to manage that.